Mars Science Laboratory Will Launch on an Atlas V 541

When mission planners are considering different launch vehicles, what they take into consideration is how much mass each launch vehicle can lift into space.

A two-stage Atlas V-541 launch vehicle will lift the Mars Science Laboratory spacecraft from Launch Complex 41 at Cape Canaveral Air Force Station, Fla. The vehicle is provided by United Launch Alliance, a joint venture of Boeing Co. and Lockheed Martin Corp.

The Atlas V-541 vehicle was selected for the Mars Science Laboratory mission because it has the right liftoff capability for the heavy weight requirements and rockets in the same family have successfully lifted NASA's Mars Reconnaissance Orbiter and New Horizons missions.

Details on the Launch Vehicle

Atlas V rockets are expendable launch vehicles (ELVs), which means they are only used once. The thee numbers in the 541 designation signify a payload fairing, or nose cone, that is approximately 5 meters (16.4 feet) in diameter; four solid-rocket boosters fastened alongside the central common core booster; and a one-engine Centaur upper stage.

The major elements of the Atlas V-541 rocket that will be used for the MSL mission are:

	Stage 1: Atlas V Rocket: Fuel and oxygen tanks that feed an engine for the ascent; powers spacecraft into Earth orbit.
	Solid Rocket Motors: Used to increase engine thrust; 4 total.
	Stage 2: Centaur: Fuel and oxidizer and the vehicle's "brains"; fires twice, once to insert the vehicle-spacecraft stack into low Earth orbit and then again to accelerate the spacecraft out of Earth orbit and on its way towards Mars.
	Payload Fairing Thin composite or nose cone to protect the spacecraft during the ascent through Earth's atmosphere.